Tilting mechanism for venetian blinds



Sept. 24, 1935. s CAMPBELL 2,015,215

TILTING MECHANISM FOR VENETIAN BLINDS Filed May 18 1935 INVENTOR STANLEYE CAMPBELL ATTORNEY L atented Sept. 24, 1935 TETING MECHANISM FORVENETIAN BLlINlDS Y Stanley ll. Campbell, Saginaw, Mich, assignor toGermain Manufacturing Company, Saginaw, Mich, a, corporation of MichiganApplication May 18, 1935, Serial No. 22,137

6 Claims.

This invention relates to, Venetian window blinds. It pertains moreparticularly to improvements in the mechanism by which the tilt rail istilted to open or close such blinds.

Tilting devices of such character are arranged to actuate the tiltingrail at an end thereof. The tilting mechanism is usually mounted in ahousing which is fixed to the head rail or to some part of the window,and is operated by pulling a cable that hangs down alongside the blind.By the term cable is meant any flexible cord, chain or the like.

The objects attained by my present improvement, as to its generalaspects, are: compactness of the actuating mechanism; no partsprojecting from the housing, except the spindle for the tilt rail;adaptability for use on blinds with wider or narrower head rails andtilt rails; and adaptability to either the right-hand or left-hand sideof a window frame; positive locking.

In respect to its mechanical operation, the advantageous resultsattained by my invention are: to provide an operating mechanism thatwill give a smooth, even rotating or tilting movement to the tilt railof a Venetian blind, without any undesirable noise in the tilting deviceitself and without vibration effects being transmitted, as noise orclatter, from the window frame through the frame of the building, so asto be audible in adjoining rooms: to-provide an actuating mechanism inwhich the pull on the cord shall be easy and virtually uniform,irrespective of the angle to which the tilt rail and slats may beinclined, that is to say, without any appreciable changes in pullresistance due to changing angularity of the moving parts, whichheretofore has been an undesirable feature of tilting devices whereinarms and links were employed that produced a variable eccentric thrustat different degrees of tilting; to provide a screwactuated tiltingdevice wherein a given distanceof cord pull shall completely tilt theslats from open to closed position with a relatively great number ofturnsof the screw, as compared with former structures in which thelength of cord movement produced only a few turns of the screw, theadvantage being that the cord wheel can now be made unusually small andcan be concealed in a compact housing, yet will exert adequate tiltingforce with very light pull on the cord; to provide a simplified andeasily detachable means for keeping the cord on the wheel; and a simpleand inexpensive means for maintaining in the screw any desired amount offrictional resistanceagainst turning and for taking up wear and avoidingback lash; and to provide a housing construction that is inexpensive tomanufacture, gives ready accessibility to the working parts and enablesthem to be rapidly and accu-' rately assembled. 5

With the foregoing and certain other objects in view, which will appearlater in the specifications, my invention comprises the devicesdescribed and claimed and the equivalents thereof.

In the drawing Fig. lis a front view of the 10 tilting mechanism as itappears with the front wall of the housing removed.

Fig. 2 is a top plan view of the housing and its associated mechanism.

Fig. 3 is a side view of the housing with one of 15 its sides removedand showing its application to wider or narrower tilt rails of a windowframe.

Fig. 4 is a perspective view of the spring device for keeping the cordin place on a screw-actuated wheel,

Fig. 5 is a perspective view of the housing as it appears with theinterior tilting mechanism removed. I

In the preferred form of the device which is chosen for purpose ofillustration, numeral I designates a conventional tiltable top rail of aVenetian blind. The housing, which is preferably made of sheet metal,comprises a front wall 2 and side walls 3, 4 formed with outwardlyprojecting flanges 5 adapted to be fastened to the head rail 6 of theVenetian blind by means of screws or otherwise. The operating mechanismis enclosed within the housing and consists of a wheel I grooved to takea cable or a cord la. The wheel is fixed to a threaded bolt or screw 8,the threads being shown diagrammatically in Fig. 3. These threads are ofrelatively fine pitch, that is, a pitch which is standard for machinebolts of corresponding size. The threads may be of usual V-shape, orsquare. The screw 8 is supported by and rotates on an end bearing Illsecured to the front wall of the housing and a bearing ll mounted in afixed support at the rear end of the housing. These bearings arepreferably in the form of conical or ball tipped screws received inrecesses in the ends of the bolt 8. Preferably the bearing II is a setscrew threaded through a bracket l2 so as to be capable of endwiseadjustment for the purpose of producing an adjustable amount of endwisethrust against bolt 50 8 and thereby produce any desired amount offrictional resistance against turning the bolt when the cord "la ispulled. The end bearing H may be locked in any adjusted position bymeans of a set nut 13. The bearing I0 may be secured 55 to the frontwall 2 of the housing by riveting, as shown, or by any other suitablemeans.

The bracket I2, which may be formed of sheet metal, serves as a supportfor the adjustable bearing II, and is connected to the side walls of thehousing 3, 4, preferably by spot welding, as is indicated in Fig. 2. p

Bracket I2 is formed with one or more inwardly projecting guide flangesH, as shown in Fig. 2.

An internally threaded rider 9 is mounted on the bolt 8, being preventedfrom turning by the guides l4 during its travel along the bolt when thelatter is rotated. vThe rider 9 may be made in the form of an elongatednut, or it may be formed of pressed metal. On the bottom face of therider is a toothed rack l5 which engages apinion IS. The pinion ismounted on a spindle IT by means of the dowel pin I611. The spindle I1is rotatable in bearings l8 on the housing walls 3, 4. An end of thespindle projects beyond the wall of the housing and is received in ahole bored axially in the tiltable top rail l. A clutch device is isfixed to the spindle l1, its prongs being likewise received in the railI so that rotating the spindle I! will tilt the rail about its axis, asis indicated by the dotted lines in Fig. 1. i

To keep the cord la normally in the groove of the wheel I I prefer toemploy the spring device illustrated in Fig. 4, consisting of a piece offlat spring or ribbon metal shaped so as to present at its middleportion a bearing face to yieldingly contact with the cord and havinglaterally looped side members 2| to give a proper degree of resilienceand to insure proper contact of the bearing portion 20 upon the cord,even though the latter become worn or stretched. The free ends 22project outwardly in opposite directions and can be releasably securedto the side walls 3, 4 of the housing. I Preferably, openings 23 areprovided in the housing, and the ends 22 are easily insertable in theopenings by squeezing the ends of the spring together and allowing themto enter the openings 23 by springing outwardly, as shown in Fig. 1.

In Fig. 3 the tilting mechanism and housing are shown as applied to thehead rail Ii of a window frame, the front wall of the housing beingflush with the edge of the rail.

The spindle I1 is positioned on the housing so that the front edges ofthe blind slats shall be located properly with respect to the windowframe when the blinds are open. For exceptionally large windows widerblind slats are used; and in such circumstances the axis of the tiltabletop rail l, and of spinde I1, will be located with respect to thehousing so that the front edges of the wider slats when opened will becorrectly alinedwith the edge of the head rail 6 of the window frame.Such diflerent position of the shaft i1 is indicated by dotted lines at24 in Fig. 5.

Obviously, the only change necessary to make in the housing in order toaccommodate either narrow or wide blind slats is to shift the locationof the bearings for spindle I1, and it is apparent that no other changeneed be made in the tilting In Fig. 3, W indicates the head rail 6 of alarge window, and w, that of a smaller window.

In operation, cord la is pulled to turn the wheel 1 and move the rider 9in the appropriate direction lengthwise of bolt 8. The pinion i6, drivenby rack l5, turns the'shaft I1 and the clutch members I9. The smallpitch of screw 8, say thirteen threads per inch for a one-half inchdiameter bolt, enables a light pull on cord In. to move the 5 rider 9easily but positively through the'required distance to produce thedesired tilt of rail I; it

. also enables wheel 'I to be made unusually small in diameter, thusminimizing the width of the housing. A steady frictional resistance ofany desired amount, counted to the pull on cord Ia, may be produced byadjusting the bearing screw I I, thus taking up all undesirable backlash in the mounting of bolt 8 and compensating for wear.

The pinion I6 and rack l5 are of fine pitch, preferably aboutthirty-two, hence there is pos sible only a negligible amount of playbetween the rack and the pinion. 'During the rotation of bolt 8 theguides I4 keep the rider 9 from rotating, and also keep the rack andpinion properly alined 2 with each other.

The tilting movement throughout its entire range is smooth and even, thepull on the cord 1 is light and uniform, without jerks or uncertainty,and noiseless, with no undesirable vibrations 25 transmitted to thewindow frame.

After the cord has been placed in the grooves of wheel I the removablekeeper, Fig. 4, can be snapped in place easily and quickly to hold thecord in position, regardless of wear on the cord or unevenness in itsdiameter.

While I have shown and described the member 7 I as being theconventional top tiltable rail of a Venetian blind, it will beunderstood that the terms tilt rail or "tiltable rail as employed in .35the foregoing description are intended to include any equivalenttiltable member, such as a tiltable roller or spool constructed andoperating in the manner of the conventional form shown.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. Means for tilting the rail of a Venetian blind, comprising astationary housing and a cable-actuated threaded bolt, cable retainingmeans, bearings on said housing so constructed and arranged as tosupport said bolt for axial rotation, a screw on the housing adapted tocreate variable amounts of lengthwise pressure of said bearings againstsaid bolt in such a manner as to frictionally regulate the resistance ofthe bolt to such cable actuation, a threaded rider on said bolt, a guidemember carried by the housing and constraining said rider against unduerotation, a rack on said rider extending lengthwise of said bolt, apinion meshing .with

said rack, a spindle for said pinion projecting beyond'a side wall ofthe housing, spindle bearings in the housing, and a clutch device on thespindle engaging said rail.

2. In an actuating mechanism for the tiltable to rail of a Venetianblind including a cable-actuated rotatably mounted threaded bolt, anadjustable end bearing for said bolt, a rider threaded on said bolt totravel lengthwise thereon, andguiding means engaging the rider in amanner to prevent undue rotation thereof, in combination, a toothed rackon said rider, and means operatively connecting said rack to an end ofsaid tiltable rail.

3. In an actuating mechanism for the tiltable rail of a Venetian blindincluding a cable-actuated rotatably mounted threaded bolt, a riderthreaded on said bolt so as to travel lengthwise thereon, and guidingmeans engaging the rider and adapted to prevent undue rotation thereof,

in combination, a rack on said rider extending lengthwise thereof, andmeans operatively connecting said rack to an end of said tiltable rail,said connecting means being arranged and adapted to support an end ofthe rail and to impart tilting movements thereto.

4. Actuating means for the tiltable rail of a Venetian blind including ahousing, a cable-actuated rotatable threaded bolt and bearings on saidhousing supporting said bolt for axial rotation, in combination,frictional adjusting means adapted to regulate the resistance of saidbolt counter to forces exerted by the cable and tending to rotate thebolt, said means comprising a threaded screw arranged and operative tovary the lengthwise pressure of said bearings against the bolt.

5. In mechanism for actuating the tiltable rail for endwise adjustmentin a manner to import to the bolt frictional resistance counter topulling efforts exerted on the cord tending to rotate the bolt, andmeans for fixing said counter bearing members in various adjustedpositions.

6. A structure as set forth in claim 3 wherein I the means operativelyconnecting the rack to an end of a tiltable rail comprises a pinionmeshing with said rack and mounted on a rotatable shaft supported inbearings on the housing.

STANLEY E. CAMPBELL.

